Can Switzerland Store Its Own CO₂ Underground? The Science Says No

New research reveals why the country’s geology makes underground carbon storage unfeasible and what alternatives might work instead

Switzerland, like most other countries, is in a race against time to reach its net-zero emissions goal by 2050, and finding ways to permanently store carbon dioxide (CO₂) is a big part of the challenge. 

This is because while renewable energy, efficiency improvements, and lifestyle changes can reduce emissions, some sectors — like waste incineration — are hard to clean up entirely. That’s where carbon capture and storage (CCS) comes in. 

But where does the captured CO₂ go? I’ve talked a lot about carbon sequestration and storage here, and most of the solutions involve using vegetation to capture CO₂, seizing the photosynthetic processes that allow them to grow. 

But this isn’t the only option available, and many countries have turned to underground storage, injecting CO₂ into rock formations deep beneath the surface. 

However, a new study set out to see if Switzerland could store its own CO₂ through in-situ mineralization, a process that permanently locks CO₂ into solid rock. Unfortunately, the results weren’t promising.

How CO₂ Can Become Rock

The idea behind in-situ mineralization is simple: inject CO₂ dissolved in water into underground rocks rich in minerals like calcium and magnesium, and chemical reactions will turn the gas into solid carbonate minerals (see the figure above as a reference). 

This isn’t something completely new, though. The approach has already worked in places like Iceland, where the CarbFix project has successfully stored thousands of tons of CO₂ in basaltic rocks. 

This is because, if the conditions are right, the process happens quickly — within a few years — locking the carbon away permanently.

But for it to work, the underground rocks have to meet very specific criteria. They need to be rich in reactive minerals, have enough porosity and permeability to allow CO₂-rich water to flow through, and be located at the right depth and temperature for mineralization to occur efficiently. 

As you can imagine, that’s a tough combination to find.

The Search for Swiss Storage Sites

Researchers from ETH Zurich scoured geological maps, analyzed rock compositions, and identified potential storage zones across Switzerland, particularly in the Alps. 

The best candidates were mafic and ultramafic rock formations which contain basalts, serpentinites, and peridotites known for their ability to store CO₂ through mineralization.

At first glance, it looked like Switzerland had the right rock types. But the closer researchers looked, the more problems emerged.

Why It Won’t Work

I know what you’re thinking. If they have the right type of rocks, why won’t this work in the Alps like it did in Iceland?

Well, the biggest roadblock is Switzerland’s geology. Unlike Iceland’s young, highly fractured basalt, Swiss alpine rocks are old, heavily deformed, and metamorphosed. 

This means that, over millions of years, heat and pressure have altered the rock structure, closing up fractures and reducing porosity and permeability to almost nothing. In simpler terms, the rocks are too compact to allow CO₂-rich water to move through them efficiently. 

As you can imagine, if the fluid can’t circulate, the mineralization reactions won’t happen.

Another challenge is temperature. In-situ mineralization works best between 90°C and 185°C, but in Switzerland, you’d have to drill more than 3,500 meters deep to reach those conditions. That makes the process expensive and technically complex.

Then there’s the water problem. Mineralization requires a huge amount of water — about 25 tons of water per ton of CO₂ stored. Switzerland already faces water management challenges, with competing demands from hydropower, agriculture, and industry. Diverting massive amounts of water for CO₂ storage could cause conflicts.

That said, even if these technical issues were solved, there would still be economic, legal, and social hurdles. 

Who would pay for the infrastructure? Would the public support CO₂ storage near their communities? What regulations would be needed to ensure safety? 

Because of these, and many other questions, the study concluded that, taken together, these challenges make in-situ CO₂ mineralization unfeasible in Switzerland — both in the near term and likely in the long run.

So Where Can Swiss CO₂ Go?

If Switzerland can’t store its CO₂ underground, what are the alternatives? 

Well, one promising option, according to the study, is storing CO₂ in deep saline aquifers, large underground water-bearing formations that can trap CO₂ safely. Researchers have already tested this near Zurich, and results suggest it could work. 

Another solution is exporting CO₂ to countries with better storage conditions, as Switzerland is already doing with Iceland’s CarbFix project.

The takeaway? Not every country can store its own CO₂ underground. While places like Iceland have ideal conditions for mineralization, Switzerland’s complex alpine geology makes it a poor candidate. 

That means Swiss climate policy needs to focus on alternatives — whether that’s improving international storage partnerships, investing in new carbon capture technologies, or simply reducing emissions at the source.

There’s no one-size-fits-all solution to carbon storage, but understanding what won’t work is just as important as figuring out what will. As we’ve talked about before, innovation through trial and error will help us through these environmental crises. 

Do you want to read more stories like this? You can now subscribe to my newsletter and join a community of over 7,500+ Earth lovers!

I’m thrilled to have you here. Stay curious, and thank you for being part of this journey!

Best,

Sílvia P-M, PhD Climate Ages

P.S. Got any topics you’d love to see covered? Hit reply — I’d love to hear from you!